


Blue's Time in Underfell

by Just_Some_Trashy_Undertale_Fan



Category: Undertale (Video Game)
Genre: All the Sin, Boys Kissing, Ecto-Penis (Undertale), Ecto-Tongue (Undertale), Ecto-Vagina (Undertale), First time writing sin, Fluff and Smut, French Kissing, Kissing, Loss of Virginity, M/M, Neck Kissing, On the couch, Other Additional Tags to Be Added, Rib Play (A Bit), Sans' Pet Rock Also Makes An Appearnace In Here, Shit I Forgot To Talk About The Collar, Skeleton Sex (Undertale), Skeletons Fucking, Smut, So Does Underfell Sans, Stuffing, Tacos, Threesome - M/M/M (Eventually), Underfell Glyde Is Also Kinda In Here, Underfell Papyrus Will Be In More Later ;3, Underfell Sans Is Top, Underswap Sans Has A Collar, Underswap Sans Is Bottom, Wait I have no life, oh well, what am I doing with my life
Language: English
Status: In-Progress
Published: 2017-01-10
Updated: 2017-01-10
Packaged: 2018-09-16 14:10:15
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,559
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9275480
Author URL: https://archiveofourown.org/users/Just_Some_Trashy_Undertale_Fan/pseuds/Just_Some_Trashy_Undertale_Fan
Summary: Blue was accidently transported to an Alternate Universe by the name of Underfell.Once there, Red quickly takes ownership of him, even though his brother wanted to.(Lots of sin) ;3





	

Blue had been sent to this universe by accident only a couple of days ago, and yet here he was. On a leash, being walked to the Fell brother's house by Red, the Sans of this universe.

He had arrived here by accident when he was trying to find his brother, and found a machine in the room he thought his brother would be in instead. Once he got here, he was greeted by a very mean, though not as mean as he was obnoxious, alternate version of Glyde. The monster wouldn't leave him alone, until the Papyrus of this universe, Edge, had shooed Glyde away. Blue, of course, was very confused and afraid at first. He still is, of course, though not as curious anymore as he is afraid. Every monster they had passed by since he was here had glared at him in ways that made him very uncomfortable.

After he had told them who he was, they seemed to immediately understand. They explained something called 'Timelines', apparently he had made it to one called 'Underfell'. The two brothers let him stay over at their house, at least until he could find his way home. Blue noticed that they hadn't worked on finding him a way home yet, though.

The night he had arrived, he was woken up by Red. Red had told him that he needed to become his in order to keep him safe. Though Blue didn't know what he had meant, he had agreed, as long as he was safe. He regretted saying yes. The pain that came next as Red tried to do something with his soul was too much, and he had passed out.

The next morning he had woken up, his soul and bones aching. He was wearing a collar, similar to the one that Red wore, but light blue instead of red. His soul was in pain as well. He looked at in in horror, there was some red inside of it.

Red had explained that it was suppose to be there. Red had put a bit of his magic inside of his soul, something about ownership, like a pet. Red also said he would know what the other was thinking, where he was, and so on. Blue was very uncomfortable with this, but got a little used to it over the next two days.

Red had just finished his duty, and was walking home with Blue since he always went with him during duty. He just wanted to keep watch over him, which honestly made Blue feel safe, as well as grateful. They got inside the house, Red was locking the excessive amount of locks on the door as Blue made his way to the kitchen.

"Watcha doing, Blue?" Red asked, finishing with the locks.

"I wanted to cook dinner, since you guys have let me stay in your house and all! Are you ok with-"

"Taco's? Yah, sounds good, I guess. Haven't had any in forever." Red said, cutting Blue off. Blue never got used to when Red would finish his thought, but what was worse was that Red said he hadn't had any taco's in forever, so Blue would just have to try his best at making these the best he could! Red smiled as he knew what Blue was thinking.

"Thanks, Blue." Red said, walking into the kitchen and watching as Blue started getting everything ready. He stopped and looked back at Red with a happy expression, he was always so happy when the Fell brothers acted nice to him, given the fact that they were in a world like this and the two sometimes didn't get along so well.

"Of course, Red! Anything for you!" Red smiled a bit as this was said.

"Anything, hmm? I'll have to remember that for later..." He said with a bit of a devious expression on his face. Blue just smiled and got back to what he was doing, Red would probably just ask him to do his laundry or clean up his room later, maybe even both, that lazy skeleton. He heard Red snicker a bit.

"What?" Blue asked.

"Nothing, nothing... Heh... Your so cute, you know that?" Blue smiled even brighter, looking back at red with a look of gratitude.

"Aww, thanks, Red!" He said, stirring the meat in the pan on their oven. He jumped a bit with a squeak as he was grabbed from behind, until he realized Red was just hugging him.

"Heh, so cute..." He said, pecking a kiss on Blue's cheek. Blue suddenly started blushing, trying to keep Red from seeing. Red just started laughing again and walked into the living room. Taking his mind off the kiss and continuing his cooking, he would have no less than the best for Red and Edge!

After finishing up cooking the meal, he brought out the taco shells, meat, cheese, lettuce, and everything else on separate little plates on the table in the living room with Red's cracked pet rock.

"Damn, that looks good, Blue!" Red said, walking up to the table and looking at everything excitedly. "When ya gonna be done preparing them?"

"They are done! Just grab a shell, put some meat in it, and then whatever else you want!" Red's face sank a bit.

"You mean, I actually have to do all that just to eat a taco?" Red said, groaning a bit. "Blue, cant you do it for me, please?" Red asked.

"Well, sure, but-"

"I'll be good with whatever you choose to put on mine, thanks!" Red said, surprising Blue yet again as his thoughts were read. He started serving up their taco's as Red went to sit on the edge of the couch.

Once Blue had found what he thought would be perfect for Red, he brought his plate to him and sit down in the middle of the couch. Red looked disappointed at where he chose to sat.

"Come on, I don't bite... Unless you ask me to~" He said with a laugh. Blue scooted over closer to him, though not completely. Red then just grabbed Blue and pulled him right against him. "There we go, isn't that better?" Blue blushed at how close they were, nodding a bit shyly. Red smiled as he picked up his first taco. Blue pushed aside his thoughts as he excitedly watched Red take his first bite. Red looked over to see that Blue was staring at him with stars in his eyes, super excited to hear what he thought of it.

"Tastes great, good job, Blue." Blue immediately squealed as he excitedly hugged Red.

"I'M SO GLAD YOU LIKE IT, RED!" Blue said, happy as can be. They continued eating their tacos as they watched some stupid yet violent show starring Mettaton... and Mettaton only. As they finished up, Blue gathered their plates and went to the kitchen to wash them.

"Hey Red, when will Edge be back?" Blue asked as he washed their plates off.

"Ah, don't worry about him. He wont be back until morning. Something with the king."

"Oh, ok, just wondering." He said, putting the plates away.

"...Hey Blue?"

"Yah?"

"You remember how you said 'Anything for you' earlier, right?"

"Yah, why? Do ya want me to clean something for ya?"

"Heh, no... I was thinking more of desert. Wanna help get me the desert I want?" Red said, his mischievous facial expression growing.

"Of course! What do ya want?" Asked Blue, walking into the living room and standing beside Red on the couch. Red sat up from the couch and started to pull Blue towards him a bit.

"Well, I was thinking of a creamy blueberry ice cream, with a cherry on top..." Before Blue could answer or ask why Red was pulling him closer, Red suddenly closed the distance between them, pulling him into a kiss. Blue started blushing furiously, but he wasn't complaining. This was his first ever real kiss, and he was loving it!

"Blue didn't know what to do, though, and decided to copy Red and put his arms around Red and twist his head a bit. Red starting to snicker, pulling back.

"First time, huh?" Red asked with a smile. Blue only started blushing more as he found he couldn't speak. "Heh, that's ok, I'll be gentle~" He pulled Blue back into the kiss, and he swear he could see fireworks somehow. It was electric, the rush, the passion... He was in love with it. He jumped a bit as something licked at his teeth. He didn't know what to do, until Red's hand had lowered down to one of his ribs and slowly caressed it. Blue gasped, and Red took the opportunity to shove his tongue into Blue's mouth, and was rewarded with finding Blue's own tongue. Their tongues danced, and it was obvious Red was the dominant one. Blue's tongue just tried to touch Red's as much as possible, loving the contact.

Red pulled back, leaving Blue with a little whine until he was pushed onto the couch, Red climbing on top of him.

"Your gonna love this, trust me~" Red said, raising Blue's shirt and exposing his ribs. He took the rest off of him and slowly started to tease at his ribs, causing Blue to moan a bit loudly. Blue quickly covered his mouth up, embarrassed by the sound he had just made. Red only looked up at him with a bit of a smug look.

"Come on now, baby... I wanna hear those moans of yours~" Red said as he grabbed Blue's wrists and pinned them above his head. He continued on with the teasing, Blue's moaning turning him on. He wanted to go further. As soon as he took his own shirt off, he started grinding against Blue roughly, earning a squeak out of him as he moaned.

"Mmm, that's a good boy~ Keep moaning for me." He said as he started to pick up the pace, grinding against him faster. Red started panting a bit, leaning in for another kiss from Blue.

Once he broke the kiss once again, he lowed himself to Blue's pants and started tugging at them a bit. Red started getting feeling of nervousness from Blue, and tried to reassure him.

"Blue, I love you so much..." He said, raising himself up again to kiss him. "Your so cute..." He said, licking his neck, causing Blue to gasp. "And caring..." He kept licking up and down Blue's neck, loving his reactions to it. "May I?" He asked, tugging at Blue's pants a bit. He could feel that Blue was feeling a bit more sure, and went for it. He removed Blue's pants and hungrily stared down at the pussy he had formed.

"All for you, Red..." Red looked up at Blue, catching the lust and need in his face. He was obviously going into heat, as he was as well. And as his first time, he should be extremely sensitive to stuff like this.

"Mmm, I cant wait to get a taste~" Blue shivered as Red gave him a predatory gaze. He leaned in for another kiss, and as soon as their mouths made contact, Blue gasped. Red had inserted a finger inside of him and was thrusting it back and forth. Blue gripped onto the couch as he moaned into the kiss. After a moment, Red inserted a second finger, and started to stretch him out. Red pulled back to take in the scene before him. Blue was blushing so hard, panting and moaning as his insides were explored for the first time, gripping the couch with both of his hands. He wanted to go further.

He took his fingers out of Blue, and he whimpered at the loss of the feeling, but gasped once again as he felt Red lick up his pussy, straight up the middle. Red got a good taste, and he wanted more. He shoved his tongue into Blue, causing him to moan louder than he had before. He suddenly put his hands on the back of Red's skull, forcing him down deeper. Red's tongue tasted all that it could, licking at Blue's inner walls, loving the taste.

"Ah~ Oh, Red! Mmm~" Red's eyes perked up to Blue, loving the state he was in, his sensitivity, the way he said his name... He was determined to hear it again. He removed Blue's hands as he got up and removed his pants. His thick, red cock flung out. Blue looked at it lovingly, wanting it inside of him so bad. Red smiled, getting turned on even more by just the thought of it. He climbed on top of Blue, impatient already at waiting to fuck him. He lined his dick up with Berry's entrance and slowly started to push in.

"Mmm- Ah, I-Its so big!" Said Blue, his tongue hanging out lewdly as Red started shoving his dick in faster. In no time, he got to the base. He looked to see Blue had tears in his eyes, and kissed them away.

"Ya ready, baby?" Red asked, pulling out slowly. Blue nodded, needy to get as much of his dick as he could. Red laughed a bit as he said, "Good."

Red suddenly thrusted back into Blue, causing him to scream in both pain and pleasure. He started fucking him at a fast pace, tears welling up in Blue's eyes again, but the pleasure outweighed the pain. Red went down and started to lick at the other side of his neck, biting it a bit was well.

"AH! R-RED, MORE!" Blue yelled, lost in the pleasure. Red started to move faster, his pace starting to become sloppy. He could feel Blue's walls start to tighten as his voice pitched up.

"RED, I'M, I'M- AH~" He couldn't continue as his first ever orgasm hit him, the pleasure too much for him. His eyes shut tight and he grabbed onto Red, never wanting to let go. Red rode through his orgasm, not even going any slower. Blue kept getting louder and louder as he became even more sensitive.

"R-RED, ITS T-TOO, MUCH! MMM~ AH~" He yelled, but Red kept going until he felt Blue's walls tighten up again, signaling his second orgasm. "ITS, AH~ H-HAPPENING AGAIN!" But Red didn't stop, he kept going faster, harder, and deeper until he could feel his coming too. With one final thrust, and biting down onto Blue's neck, he went in as deep as he could and filled up Blue's pussy as Blue reached his climax at the same time, both of them screaming out in pleasure.

Once they both calmed down a bit, still gasping for breath, Red pulled out and landed on top of Blue, too tired to move. He started to lick at the spot on Blue's neck where he bit down. As they both gasped for breath, Blue spoke up.

"I... I love you, Red..." Blue said shyly, his voice hurting a bit from all the yelling. Red looked into his eyes, seeing heart in them, loving the sight of him.

"I love you too, Blue." He said, and Blue's eyes somehow lit up even more as he smiled and hugged Red affectionately, cuddling into him.

Too tired to do anything, they both lay on the couch and cuddled into each other, slowly dozing off into sleep.

**Author's Note:**

> (Chapter 1 Notes)
> 
> Hello!
> 
> This is actually my first time writing smut...
> 
> Did I do good? (Probably not, sorry lol)
> 
> This was actually suppose to be a fontcest stories with requests and stuff kinda thing... but it turned into this. -_-
> 
> If you guys still want that, please let me know!
> 
> But for now, please enjoy this one! :)
> 
> I think the tags explain it all... But if ya still have questions/suggestions/etc., feel free to comment! :)
> 
> Thank you all so much for reading, and have a great day!


End file.
